Inhalable polymeric microparticles as pharmaceutical porous powder for drug administration

Int J Pharm. 2022 Nov 25:628:122325. doi: 10.1016/j.ijpharm.2022.122325. Epub 2022 Oct 26.


In this work, the production of inhalable polymeric microparticles with modulable porosity is described. The starting polymeric material was the PHEA-g-RhB-g-PLA graft copolymer, which was suitably processed by spray drying (SD). Thanks to the addition of AB (weight percentage equal to 10 and 20 % with respect to the polymer) in the liquid feed, three biocompatible matrices were obtained with an increasing porosity in terms of pore volume (from 0.015 to 0.024 cc/g) and pore average diameter (from 1.942 to 3.060 nm), a decreasing tapped density values (from 0.75 to 0.50), and favorable aerosolization characteristics. These differences were highlighted also by a significant increase in the release of Rapamycin from the sample which showed the higher porosity (31.0 wt% after 24 hrs incubation) than the sample with the lowest porosity (14.9 wt%) in simulated lung fluid.

Keywords: Porous microparticles; Pulmonary administration; Rapamycin; l-aspartamide (PHEA); α,β-Poly(N-2-hydroxyethyl)-D.

MeSH terms

  • Administration, Inhalation
  • Drug Carriers*
  • Particle Size
  • Polymers*
  • Porosity
  • Powders


  • Powders
  • Polymers
  • Drug Carriers